The prestigious Chinese Academy of Sciences has published a paper by Professor Yang Juan confirming their high power test results. At an input power of 2.5kW, their 2.45GHz EmDrive thruster provides 720mN of thrust. The results have clearly been subject to extensive peer review following the NWPU 2010 paper. The measurements were made on a national standard, thrust measurement device, used for Ion Engine development. Details of the measurement system and calibration data are given in the paper. A professional English translation is given here: http://www.emdrive.com/yang-juan-paper-2012.pdf

Well, newer than the last comment in any case.

« Last Edit: 04/29/2013 12:54 AM by JBF »

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"In principle, rocket engines are simple, but that’s the last place rocket engines are ever simple." Jeff Bezos

At an input power of 2.5kW, their 2.45GHz EmDrive thruster provides 720mN of thrust.

A photon has energy E = hf and momentum p = hf / c = E / c

F = dp/dt = dE/dt / c

So even if all the energy was converted into photons all emited in the desired direction, that would make a force:

F = 2.5e3/3e8 = 8e-6 N

That's 90 000 times less than 720 mN.

Where am I wrong?

Read the papers. You are missing the q factors, relativity etc. work thru the math in the paper then make a post. I did it and even though I'm not entirely convinced I am thinking that it is a possibility- especially given that the effect has been independently confirmed. It needs a serious look.

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Given finite cash, if we want to go to Mars then we should go to Mars.

Yep.. free energy. Forget the heat death of the universe, we will just keep creating additional mass locally.

Hmm.. actually perhaps this answers the Fermi paradox. It may simply be impossible for a species spread across the stars with access to free energy and mass to have the discipline to not create more living space exponentially, and eventually suck its local group into a black hole.

Not sure this is related to the emdrive, think this is that Q thruster concept.regardless, the abstract makes it sound more negative than positive.

"..Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the "null" test article)."

Not sure this is related to the emdrive, think this is that Q thruster concept.regardless, the abstract makes it sound more negative than positive.

"..Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the "null" test article)."

Like the placebo in a drug trial showing the same "effect".

From my limited understanding of the topic I wasn't sure why these two were linked together in the Wired article, are they really that closely related?

Not sure this is related to the emdrive, think this is that Q thruster concept.regardless, the abstract makes it sound more negative than positive.

"..Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the "null" test article)."

Like the placebo in a drug trial showing the same "effect".

From my limited understanding of the topic I wasn't sure why these two were linked together in the Wired article, are they really that closely related?

i think they are part of a broad classification of propulsion, etc labelled Space drives? maybe that is why?

Not sure this is related to the emdrive, think this is that Q thruster concept.regardless, the abstract makes it sound more negative than positive.

"..Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the "null" test article)."

Like the placebo in a drug trial showing the same "effect".

From my limited understanding of the topic I wasn't sure why these two were linked together in the Wired article, are they really that closely related?

I dont think they are very similar at all. - The Q thruster attempts to act upon underlying virtual particles to produce thrust without reaction mass while the EMdrive is trying a scheme of pumping microwaves into a sealed high Q (which equates to highly internally reflective) chamber, where one end is a different geometry to the other.

Anyone notice Harold 'warp drive' White is one of the authors on this?

Reading the NASA papers (which is damm strange. It's more like an extended abstract. Is this due to be presented somewhere) shows it's nothing to do with the Chinese EM thruster work but is Sonny White's Quantum Vacuum Thruster

Here's the weird thing.

"within a stainless steel vacuum chamber with the door closed but at ambient atmospheric pressure. "Personally I could see that 35-50 micro Newton (1x10^-6) being a microwave heating effect on the air.

Show that with door on the chamber closed and the air pumped out makes the situation much more interesting.

Clearly the dear old Wired reports have conflated the QVT work with the EM thruster work, although I have to admit from a superficial reading the two seem similar.

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Manual frequency control was required throughout the test. Thrust was observed on both testarticles, even though one of the test articles was designed with the expectation that it would not producethrust. Specifically, one test article contained internal physical modifications that were designed to producethrust, while the other did not (with the latter being referred to as the “null” test article).

This looks like an issue to me that indicates a problem with their setup. Also, if I interpret their video on vimeo correctly, then their test setup has the problem that their power supply is in a different reference frame. From what I remember from previous discussions on the topic, that may distort the results:

Manual frequency control was required throughout the test. Thrust was observed on both testarticles, even though one of the test articles was designed with the expectation that it would not producethrust. Specifically, one test article contained internal physical modifications that were designed to producethrust, while the other did not (with the latter being referred to as the “null” test article).

This looks like an issue to me that indicates a problem with their setup. Also, if I interpret their video on vimeo correctly, then their test setup has the problem that their power supply is in a different reference frame. From what I remember from previous discussions on the topic, that may distort the results:

Can you explain more about the power supply being in a different reference frame?Surely it is not. It is at rest compared to the test device.